Vehicle air conditioning device

Abstract

The purpose of the present invention is to cope with the need for a rapid increase in the indoor temperature when the outside air temperature is particularly low or when heating is started, and to perform efficient heat exchange even when a refrigerant circuit using a refrigerant having a low critical temperature is used. Provided is an air-conditioning device for a vehicle, comprising a refrigerant circuit, a heat medium circuit in which a heat medium temperature-adjusted by the refrigerant circuit circulates, and an air-conditioning unit in which a plurality of heat exchangers through which the heat medium flows are disposed in an air flow path, and which blows temperature-adjusted air into the interior of the vehicle. The refrigerant circuit includes a first refrigerant / heat medium heat exchanger and a second refrigerant / heat medium heat exchanger that are provided in this order in the circulation direction of the refrigerant and that dissipate heat of the refrigerant to the heat medium, and the heat medium circuit includes a flow path switching unit. The flow path switching unit switches a flow path through which a heat medium that has passed through either the first refrigerant / heat medium heat exchanger or the second refrigerant / heat medium heat exchanger flows into at least one of the plurality of heat exchangers. And a flow path through which the heat medium that has passed through both the first refrigerant / heat medium heat exchanger and the second refrigerant / heat medium heat exchanger flows into the plurality of heat exchangers.

Description

Technical Field

[0001] The present invention relates to an air conditioning device for a vehicle. Background Art

[0002] A vehicle air conditioning device using a heat pump type refrigerant circuit is known. Such a vehicle air conditioning device is usually composed of a refrigerant circuit, a heat medium circuit, and a vehicle interior air conditioning unit. The refrigerant circuit includes a compressor, a condenser for heat dissipation, an expansion mechanism, and an evaporator for heat absorption. The heat medium circuit is used to circulate the heat medium after heat exchange with the refrigerant in the condenser or evaporator. The vehicle interior air conditioning unit is internally provided with a heat exchanger through which the heat medium circulating in the heat medium circuit passes. The heat medium that has become high temperature due to heat dissipation in the condenser is transported to the heat exchanger of the vehicle interior air conditioning unit, thereby performing a heating operation. The heat medium that has become low temperature due to heat absorption in the evaporator is transported to the heat exchanger of the vehicle interior air conditioning unit, thereby performing a cooling operation.

[0003] In the past, the aforementioned vehicle air conditioning device switched the flow path of the heat medium circuit in accordance with various operation modes, and when improving the efficiency of cooling operation and heating operation, operations such as allowing the heat medium to flow in series through multiple heat exchangers arranged inside the vehicle interior air conditioning unit were performed (see the following patent document 1).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-45068

[0005] According to the above-mentioned prior art, with respect to the multiple heat exchangers provided in the vehicle interior air conditioning unit, the heating efficiency is improved by allowing the high-temperature heat medium to flow through all the heat exchangers during the heating operation. However, the temperature range of the heat medium flowing through the multiple heat exchangers in the vehicle interior air conditioning unit is consistent, so there is a problem that sufficient efficiency improvement cannot be expected when the outside air temperature is particularly low or the indoor temperature needs to rise rapidly.

[0006] In addition, considering the environmental load, the use of natural refrigerants such as CO2 and propane as refrigerants flowing in the refrigerant circuit has been studied. Among such natural refrigerants, there are refrigerants with low critical temperatures. The high-pressure side of the refrigerant circuit cycle becomes a supercritical condition, and it does not condense like refrigerants such as Freon, but becomes a cooling process in which the temperature gradually decreases. Therefore, when using a refrigerant with a low critical temperature, there is a problem that it is difficult to perform efficient heat exchange in a refrigerant heat medium heat exchanger such as a condenser in a conventional refrigerant circuit. Summary of the invention

[0007] The subject of the present invention is to cope with such a problem. That is, the subject of the present invention is to achieve, in a vehicle air conditioning device having a heat pump refrigerant circuit, efficiency improvements such as being able to cope with a demand for a rapid rise in indoor temperature when the outside air temperature is particularly low or when heating is started, and to be able to perform efficient heat exchange even when a refrigerant circuit using a refrigerant with a low critical temperature is used.

[0008] In order to solve such a problem, one embodiment of the present invention has the following structure. That is, a vehicle air conditioning device of one embodiment of the present invention comprises: a refrigerant circuit; a heat medium circuit for circulating a heat medium heated or cooled by the refrigerant circuit; and an air conditioning unit, wherein a plurality of heat exchangers are arranged in an air flow passage for flowing the heat medium circulating in the heat medium circuit, the air passing through the air flow passage is temperature-controlled and supplied to the vehicle interior, the refrigerant circuit comprises a first refrigerant-heat medium heat exchanger and a second refrigerant-heat medium heat exchanger which are arranged in sequence along the circulation direction of the refrigerant and dissipate the heat of the refrigerant to the heat medium circulating in the heat medium circuit, the heat medium circuit comprises a flow passage switching section, the flow passage switching section switching so that the heat medium passing through either the first refrigerant-heat medium heat exchanger or the second refrigerant-heat medium heat exchanger flows into the flow passage of at least one of the plurality of heat exchangers, and so that the heat medium passing through both the first refrigerant-heat medium heat exchanger and the second refrigerant-heat medium heat exchanger flows into the flow passage of the plurality of heat exchangers.

[0009] According to the vehicle air conditioning device of the present invention having such characteristics, it is possible to achieve efficiency improvements in response to the need for a rapid increase in indoor temperature when the outside air temperature is particularly low or when heating is started, and efficient heat exchange can be performed even in a refrigerant circuit using a refrigerant with a low critical temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is an explanatory diagram showing a schematic configuration of a vehicle air conditioning apparatus according to an embodiment of the present invention. Figure 2 This is a block diagram showing a schematic configuration of a control unit of the vehicle air conditioning apparatus according to the embodiment of the present invention. Figure 3 It is an explanatory diagram showing the flow of the heat medium when the first heating mode is executed in the vehicle air conditioning apparatus according to the embodiment of the present invention. Figure 4 It is an explanatory diagram showing the flow of the heat medium when the second heating mode is executed in the vehicle air conditioning apparatus according to the embodiment of the present invention. Figure 5It is an explanatory diagram showing the flow of heat medium when the cooling mode is executed in the vehicle air conditioning apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals in different drawings represent parts with the same functions, and repeated descriptions in the drawings will be appropriately omitted.

[0012] like Figure 1 As shown, a heat medium circuit 10 according to an embodiment of the present invention is applied to a vehicle air conditioning apparatus 1 that is mounted on a vehicle and performs temperature control of vehicle-mounted equipment and air conditioning in a vehicle interior, for example. The vehicle air conditioning device 1 includes: a refrigerant circuit R as a heat source; a heat medium circuit 10 that circulates a heat medium whose temperature is controlled by heat exchange with the refrigerant; and an air conditioning unit 80 that supplies air whose temperature is regulated by the heat medium circulating in the heat medium circuit 10 into the vehicle interior.

[0013] exist Figure 1 In the example shown, the refrigerant circuit R is a closed circuit that circulates the refrigerant by sequentially connecting the compressor 11, the condenser 12 (the first condenser 121 and the second condenser 122), the expansion valve 13, the evaporator 14, and the accumulator 15 with refrigerant piping. The condenser 12 includes the first condenser 121 and the second condenser 122 that are sequentially arranged from the upstream side in the circulation direction of the refrigerant in the refrigerant circuit R. In addition, the refrigerant circuit R may also be a circuit that includes a receiver on the downstream side of the condenser 12, for example.

[0014] The heat medium circuit 10 includes a high-temperature heat medium passage 20 , a low-temperature heat medium passage 30 , a temperature control target heat medium passage 40 , a container 50 , a first passage switching unit V1 and a second passage switching unit V2 as passage switching units, a four-way valve 61 , and a four-way valve 62 .

[0015] The high-temperature heat medium flow path 20 is provided with a high-temperature heat exchanger 21, which is a refrigerant heat medium heat exchanger that is integrated with the condenser 12 in the refrigerant circuit R and performs heat exchange between the heat medium and the refrigerant. The high-temperature heat exchanger 21 includes a first high-temperature heat exchanger 211 (first refrigerant heat medium heat exchanger) that is integrated with the first condenser 121 and performs heat exchange between the heat medium and the refrigerant, and a second high-temperature heat exchanger 212 (second refrigerant heat medium heat exchanger) that is integrated with the second condenser 122 and performs heat exchange between the heat medium and the refrigerant. In the high-temperature heat medium flow path 20, the heat medium pumped by the first pump P1 becomes high temperature and circulates due to the heat dissipation of the refrigerant in the condenser 12 in the refrigerant circuit R while passing through the high-temperature heat exchanger 21.

[0016] The high-temperature heat medium flow path 20 includes a first high-temperature heat medium flow path 201 and a second high-temperature heat medium flow path 202, wherein the first high-temperature heat medium flow path 201 includes a first high-temperature heat exchanger 211, and the second high-temperature heat medium flow path 202 includes a second high-temperature heat exchanger 212. The first high-temperature heat medium flow path 201 and the second high-temperature heat medium flow path 202 can be made into independent flow paths by controlling the first flow path switching unit V1, the four-way valve 61, and the four-way valve 62, and can be connected to each other to form a flow path including the first high-temperature heat exchanger 211 and the second high-temperature heat exchanger 212.

[0017] The low-temperature heat medium flow channel 30 is provided with a low-temperature heat exchanger 31, which is integrated with the evaporator 14 in the refrigerant circuit R to perform heat exchange between the heat medium and the refrigerant. The heat medium pumped by the second pump P2 becomes low-temperature and circulates during the period of passing through the low-temperature heat exchanger 31 due to the heat absorption of the refrigerant in the evaporator 14 in the refrigerant circuit R.

[0018] The temperature-controlled heat medium flow path 40 includes a battery heat exchanger 41 for controlling the temperature of a battery (BATT) in an electric vehicle, a motor heat exchanger 42 for controlling the temperature of a travel motor (MOT), an inverter heat exchanger 43 for controlling the temperature of an inverter (INV), a PCU (Power Control Unit) heat exchanger 44 for controlling the temperature of a power control unit, and an outdoor heat exchanger 45. In the temperature-controlled heat medium flow path 40, the heat medium is pumped by the third pump P3.

[0019] In addition, in the temperature control target heat medium flow path 40, the first flow path 401 including the battery heat exchanger 41, the second flow path 402 including the outdoor heat exchanger 45, and the third flow path 403 are connected by the second flow path switching unit V2, and the third flow path 403 includes the motor heat exchanger 42, the inverter heat exchanger 43, and the PCU heat exchanger 44. The first flow path 401, the second flow path 402, and the third flow path 403 can be made independent of each other by controlling the second flow path switching unit V2, and can also be made partially or entirely connected.

[0020] The container 50 includes an inlet 52 connected to the high-temperature heat medium flow path 20 , an inlet 54 connected to the temperature control target heat medium flow path 40 , and an outlet 53 connected to the low-temperature heat medium flow path 30 . In the high-temperature heat medium flow path 20, a connection portion 28 connected to the inlet 52 is provided on the heat medium upstream side of the first pump P1. In the temperature control target heat medium flow path 40, a connection portion 48 connected to the inlet 54 is provided on the heat medium downstream side of each temperature control target heat exchanger. In the low-temperature heat medium flow path 30, a connection portion 38 connected to the outlet 53 is provided on the heat medium upstream side of the second pump P2.

[0021] That is, Figure 1 As shown, the container 50 is connected to the upstream side of the first pump P1 in the high-temperature heat medium flow channel 20 through the inlet 52, is connected to the heat medium downstream side of the motor heat exchanger 42 in the temperature control object heat medium flow channel 40 through the inlet 54, and is connected to the heat medium upstream side of the second pump P2 in the low-temperature heat medium flow channel 30 through the outlet 53.

[0022] Furthermore, a safety valve 57 is provided on the path from the connection portion 28 to the inlet 52 of the container 50. Thus, when the heat medium circulated in the high-temperature heat medium flow path 20 expands due to a rise in temperature, and the amount of the heat medium becomes larger than the circuit capacity of the high-temperature heat medium flow path 20, the safety valve 57 is opened, and the heat medium flows from the high-temperature heat medium flow path 20 into the container 50 via the inlet 52.

[0023] Similarly, a safety valve 58 is provided on the path from the connection portion 48 to the inlet 54 of the container 50. Thus, when the heat medium circulated in the temperature control target heat medium flow path 40 expands due to the increase in temperature, and the amount of the heat medium becomes larger than the circuit capacity of the temperature control target heat medium flow path 40, the safety valve 58 is opened, and the heat medium flows from the temperature control target heat medium flow path 40 into the container 50 via the inlet 54.

[0024] On the other hand, when the heat medium circulating in the low-temperature heat medium passage 30 contracts due to a decrease in temperature, the heat medium stored in the container 50 flows out from the outflow port 53 and flows into the low-temperature heat medium passage 30 through the connection portion 38 .

[0025] As the heat medium circulated in the heat medium circuit 10, water without additives or water mixed with additives such as antifreeze and preservatives may be used, and liquid heat medium such as oil may also be used.

[0026] The air conditioning unit 80 includes an air inlet 83 for sucking air (external air or internal air) into the air conditioning unit 80 , an air flow path 84 through which the air sucked from the air inlet 83 passes, and a first heat exchanger 81 and a second heat exchanger 82 disposed in the air flow path 84 through which the heat medium circulating in the heat medium circuit 10 flows.

[0027] In the air conditioning unit 80 , air introduced from the air inlet 83 into the air flow path 84 is ventilated toward the first heat exchanger 81 and the second heat exchanger 82 to exchange heat with the heat medium in the first heat exchanger 81 and the second heat exchanger 82 , thereby sending the temperature-controlled air into the vehicle interior.

[0028] Figure 2 FIG. 2 shows a schematic structure of a control unit 100 that is responsible for controlling the vehicle air conditioning device 1. Figure 2 In the following, illustration and description of configurations that are not directly related to the operation of the vehicle air conditioning apparatus 1 of the present embodiment are appropriately omitted.

[0029] The control unit 100 is connected to the vehicle controller 200 through the vehicle communication bus to send and receive information. The vehicle controller 200 is responsible for the overall control of the vehicle including the driving control of the driving motor, the inverter and the power control unit, and the charge and discharge control of the battery. For example, a computer with a processor such as an ECU (Electronic Control Unit) or a microcomputer can be applied to the control unit 100 and the vehicle controller 200.

[0030] The following sensors and devices are connected to the control unit 100, and the outputs of these sensors and the like are input to the control unit 100. Specifically, the control unit 100 is connected with a temperature sensor TC1 for detecting the temperature of the heat medium after flowing into the high-temperature heat exchanger 21 and being heated by the condenser 12, a temperature sensor TC2 for detecting the temperature of the heat medium after flowing into the low-temperature heat exchanger 31 and being cooled by the evaporator 14, a temperature sensor TC80 for detecting the temperature of the heat medium flowing into the first heat exchanger 81 and the second heat exchanger 82 of the air conditioning unit 80, a battery temperature sensor TC41 for detecting the temperature of the battery (either the temperature of the battery itself or the temperature of the heat medium flowing into or out of the battery heat exchanger 41), and a temperature sensor TC50 for detecting the temperature of the motor. A motor temperature sensor TC42 for detecting the temperature of the motor (either the temperature of the motor itself or the temperature of the heat medium flowing in or out of the motor heat exchanger 42), an inverter temperature sensor TC43 for detecting the temperature of the inverter (either the temperature of the inverter itself or the temperature of the heat medium flowing in or out of the inverter heat exchanger 43), a PCU temperature sensor TC44 for detecting the temperature of the power control unit (either the temperature of the PCU itself or the temperature of the heat medium flowing in or out of the PCU heat exchanger 44), and an air conditioning operating unit 300.

[0031] On the other hand, the expansion valve 13, the first pump P1, the second pump P2, the third pump P3, the first flow path switching unit V1, the second flow path switching unit V2, and the four-way valves 61 and 62 are connected to the output side of the control unit 100. The control unit 100 controls these components based on the output of each sensor, the setting input to the air conditioning operation unit 300, and the information from the vehicle controller 200.

[0032] In the vehicle air conditioning device 1 thus constructed, by controlling the first flow path switching unit V1, the second flow path switching unit V2 and the four-way valves 61, 62 by the control unit 100, it is possible to switch the high-temperature heat medium flow path 20, the low-temperature heat medium flow path 30 and the temperature control target heat medium flow path 40 of the heat medium circuit 10 to become independent flow paths or connected flow paths.

[0033] In addition, in the vehicle air conditioning device 1, the control unit 100 controls the first flow path switching unit V1, the second flow path switching unit V2 and the four-way valves 61 and 62, so that one or both of the high-temperature heat medium flow path 20 and the low-temperature heat medium flow path 30 of the heat medium circuit 10 are selectively connected to the first heat exchanger 81 or the second heat exchanger 82 according to the air conditioning purpose and the target air conditioning temperature.

[0034] Thus, the heat medium whose temperature has been adjusted in one or both of the high-temperature heat medium flow path 20 and the low-temperature heat medium flow path 30 flows into at least one of the first heat exchanger 81 and the second heat exchanger 82 via at least one of the first flow path switching unit V1 and the second flow path switching unit V2 .

[0035] At this time, the control unit 100 can control to set the first high-temperature heat medium flow channel 201 and the second high-temperature heat medium flow channel 202 as connected flow channels in the high-temperature heat medium flow channel 20, and make the heat medium that has passed through the first high-temperature heat exchanger 211 and the second high-temperature heat exchanger 212 flow to both the first heat exchanger 81 and the second heat exchanger 82. In this case, the heat medium that has passed through the second high-temperature heat exchanger 212 and the first high-temperature heat exchanger 211 in sequence flows to the first heat exchanger 81 that is arranged on the upstream side of the air flow channel 84 after flowing through the second heat exchanger 82 that is arranged on the downstream side of the air flow channel 84.

[0036] In addition, the control unit 100 is capable of controlling to set the first high-temperature heat medium flow channel 201 and the second high-temperature heat medium flow channel 202 as independent flow channels, and to make the heat medium passing through the first high-temperature heat exchanger 211 flow to the second heat exchanger 82 arranged on the downstream side of the air flow channel 84, and to make the heat medium passing through the second high-temperature heat exchanger 212 flow to the first heat exchanger 81 arranged on the upstream side of the air flow channel 84.

[0037] The control unit 100 controls the first flow path switching unit V1 to make the heat medium that flows into the high-temperature heat exchanger 21 of the high-temperature heat medium flow path 20 and is heated by the condenser 12 flow to the first heat exchanger 81 and the second heat exchanger 82 disposed in the air conditioning unit 80, thereby heating the air that passes through the air flow path 84 of the air conditioning unit 80. By supplying the air heated by the air conditioning unit 80 to the vehicle interior, the vehicle interior can be heated.

[0038] The control unit 100 controls the heat medium that flows into the low-temperature heat exchanger 31 of the low-temperature heat medium flow path 30 and is cooled by the evaporator 14 to flow to the first heat exchanger 81 and the second heat exchanger 82 disposed in the air conditioning unit 80 through the first flow path switching unit V1, thereby cooling the air that has passed through the air conditioning unit 80. The air cooled by the air conditioning unit 80 is supplied to the vehicle interior, thereby cooling the vehicle interior.

[0039] Furthermore, the control unit 100 controls the first flow path switching unit V1, the second flow path switching unit V2, and the four-way valves 61 and 62 to circulate the high-temperature heat medium in the high-temperature heat medium flow path 20 or the low-temperature heat medium in the low-temperature heat medium flow path 30 to the temperature control target heat medium flow path 40 according to the target temperature of each temperature control target heat exchanger (battery heat exchanger 41, motor heat exchanger 42, inverter heat exchanger 43, and PCU heat exchanger 44) included in the temperature control target heat medium flow path 40. By circulating the heat medium whose temperature is controlled in the high-temperature heat medium flow path 20 or the low-temperature heat medium flow path 30 to the temperature control target heat medium flow path 40, the temperature of the battery heat exchanger 41, the motor heat exchanger 42, the inverter heat exchanger 43, and the PCU heat exchanger 44 can be controlled.

[0040] The operation of the vehicle air conditioning device 1 thus constructed is described below. In the vehicle air conditioning device 1 of the present embodiment, various operation modes such as a first heating mode, a second heating mode, a cooling mode, a dehumidification mode, and a temperature control mode can be executed, wherein the first heating mode can cope with the rapid increase in the vehicle interior temperature when the outside air temperature is particularly low or when the vehicle air conditioning device is started, the increase in the vehicle interior temperature in the second heating mode is lower than the increase in the vehicle interior temperature in the first heating mode, and the temperature control mode includes cooling or warming up of vehicle-mounted equipment.

[0041] When executing the above-mentioned various operation modes, in the refrigerant circuit R of the vehicle air conditioning device 1, the rotation speed of the compressor 11 is appropriately controlled by the control unit 100, and the air supplied to the vehicle interior is adjusted to the target temperature by utilizing the heat dissipation of the condenser 12 and the heat absorption of the evaporator 14, so as to perform air conditioning in the vehicle interior. In the refrigerant circuit R, the refrigerant circulates as follows.

[0042] That is, the high-pressure gas refrigerant ejected from the compressor 11 dissipates heat and liquefies and condenses by heat exchange with the heat medium passing through the high-temperature heat exchanger 21 in the condenser 12, and becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flowing out of the condenser 12 is decompressed and expanded by the expansion valve 13, becomes a low-pressure refrigerant, and flows into the evaporator 14. The low-pressure refrigerant flowing into the evaporator 14 evaporates by heat exchange with the heat medium passing through the low-temperature heat exchanger 31 in the evaporator 14, becomes a gas refrigerant, flows out of the evaporator 14, and returns to the compressor 11 via the accumulator 15.

[0043] Hereinafter, a first heating mode capable of responding to a rapid increase in vehicle interior temperature, a second heating mode in which the increase in vehicle interior temperature is lower than the increase in vehicle interior temperature in the first heating mode, and a cooling mode will be described.

[0044] (About heating mode) (1) First heating mode The first heating mode of this embodiment is a heating mode that can cope with the rapid increase in temperature in the vehicle interior, and is an action mode that utilizes the waste heat from the second high-temperature heat exchanger 212 and various vehicle-mounted equipment to warm up the battery and uses the outdoor heat exchanger 45 as a heat absorption source to heat the vehicle interior and each seat.

[0045] When the first heating mode is executed, the first high-temperature heat medium flow channel 201 and the second high-temperature heat medium flow channel 202 in the high-temperature heat medium flow channel 20 are set as independent flow channels, and the heat medium heated in the first high-temperature heat exchanger 211 of the first high-temperature heat medium flow channel 201 is introduced into the second heat exchanger 82. In addition, the heat medium heated in the second high-temperature heat exchanger 212 of the second high-temperature heat medium flow channel 202 is introduced into the first heat exchanger 81. The flow of the heat medium in the first heating mode is as follows Figure 3 shown.

[0046] exist Figure 3 In the figure, regarding the flow of heat medium, black solid lines represent pipes for circulation of high-temperature heat medium, single-dotted dashed lines represent pipes for circulation of low-temperature heat medium, and gray solid lines represent pipes for circulation of heat medium in a temperature range between high and low temperatures. The control unit 100 controls the first flow path switching unit V1 , the second flow path switching unit V2 , and the four-way valves 61 , 62 to circulate the heat medium in the heat medium circuit 10 as follows.

[0047] The control unit 100 sets the first high-temperature heat medium flow channel 201 and the second high-temperature heat medium flow channel 202 of the high-temperature heat medium flow channel 20 as independent flow channels, and sets the first flow channel 401 and the third flow channel 403 in the temperature adjustment target heat medium flow channel 40 as flow channels connected to the second high-temperature heat medium flow channel 202. In addition, the control unit 100 connects the second heat exchanger 82 to the first high-temperature heat medium flow channel 201, and connects the first heat exchanger 81 to the second high-temperature heat medium flow channel 202.

[0048] Thus, the heat medium heated by passing through the first high-temperature heat exchanger 211 flows to the second heat exchanger 82 via the first flow path switching unit V1, and the heat medium flowing into the second heat exchanger 82 exchanges heat with the air passing through the air flow path 84. The heat medium flowing through the second heat exchanger 82 repeatedly circulates through the four-way valve 62 and returns to the first high-temperature heat exchanger 211 through the first pump P1.

[0049] On the other hand, the heat medium heated by passing through the second high-temperature heat exchanger 212 flows into the first heat exchanger 81 via the four-way valve 62 and the first flow path switching unit V1, and exchanges heat with the air passing through the air flow path 84. The heat medium flowing out of the first heat exchanger 81 flows into the battery heat exchanger 41 via the first flow path switching unit V1, the four-way valve 61, and the second flow path switching unit V2 through the third pump P3, and heats the battery.

[0050] The heat medium that has passed through the battery heat exchanger 41 flows into the PCU heat exchanger 44, the inverter heat exchanger 43, and the motor heat exchanger 42 in sequence through the second flow path switching unit V2. The heat medium that has passed through the PCU heat exchanger 44, the inverter heat exchanger 43, and the motor heat exchanger 42 and has exchanged heat with each vehicle-mounted device and recovered waste heat is heated in the ECH (Electric Coolant Heater: electric cooling medium heater) 46 as needed, and repeatedly circulates back to the second high-temperature heat exchanger 212 through the four-way valve 61. Thus, the vehicle interior can be heated by the first heat exchanger 81 and the second heat exchanger 82 .

[0051] During the process of the heat medium heated by the first high-temperature heat exchanger 211 circulating in the first high-temperature heat medium flow channel 201, if the heat medium expands due to the increase in temperature and the amount of heat medium becomes greater than the circuit capacity, the safety valve 57 becomes open, and the heat medium flows from the inlet 52 through the connection part 28 into the container 50 and is stored.

[0052] On the other hand, the control unit 100 controls the first flow channel switching unit V1 and the second flow channel switching unit V2 so that the low-temperature heat medium flow channel 30 and the second flow channel 402 of the temperature control object heat medium flow channel 40 become connected flow channels, and the heat medium cooled by passing through the low-temperature heat exchanger 31 circulates to the low-temperature heat medium flow channel 30 and the second flow channel 402 of the temperature control object heat medium flow channel 40. That is, the heat medium cooled by the low-temperature heat exchanger 31 flows into the outdoor heat exchanger 45 through the first flow switching part V1 and the second flow switching part V2, and returns to the low-temperature heat exchanger 31 through the second flow switching part V2 and the second pump after exchanging heat with the outside air.

[0053] By repeating the above cycle, the outdoor heat exchanger 45 can be used as a heat absorption source. In the flow channel formed by connecting the low-temperature heat medium flow channel 30 and the second flow channel 402 of the temperature control target heat medium flow channel 40, if the heat medium shrinks due to a drop in temperature and the amount of the heat medium becomes smaller than the circuit capacity, the heat medium stored in the container 50 flows out from the outflow port 53 and flows into the low-temperature heat medium flow channel 30 through the connection portion 38.

[0054] As described above, in the first heating mode, the heat medium heated in the first high temperature heat exchanger 211 flows into the second heat exchanger 82 disposed on the downstream side of the air flow direction of the two heat exchangers of the air conditioning unit 80, namely, the first heat exchanger 81 and the second heat exchanger 82. At the same time, the heat medium heated in the second high temperature heat exchanger 212 flows into the first heat exchanger 81 disposed on the upstream side of the air flow direction.

[0055] Here, in the refrigerant circuit R, since the first high-temperature heat exchanger 211 is arranged on the upstream side of the refrigerant circulation direction relative to the second high-temperature heat exchanger 212, the heat medium heated in the first high-temperature heat exchanger 211 is at a higher temperature than the heat medium heated in the second high-temperature heat exchanger 212. Therefore, the heat medium circulating in the first high-temperature heat medium flow path 201 is at a higher temperature than the heat medium circulating in the second high-temperature heat medium flow path 202, and a lower temperature heat medium flows into the first heat exchanger 81 than the second heat exchanger 82.

[0056] Therefore, the air introduced into the air flow channel 84 is preheated in the first heat exchanger 81 before passing through the second heat exchanger 82, and is further heated by the higher temperature heat medium in the second heat exchanger 82, so that efficient heat exchange can be performed between the heat medium and the air, which can improve the efficiency during heating operation. Furthermore, by using two condensers in the refrigerant circuit and performing heat exchange between the refrigerant and the heat medium in two stages, efficient heating operation can be achieved even with a refrigerant having a low critical temperature such as CO 2 .

[0057] (2) Second heating mode The second heating mode of the present embodiment is an operation mode in which the battery is warmed up using waste heat from various other vehicle-mounted devices and the vehicle interior and each seat are heated using the outdoor heat exchanger 45 as a heat absorption source.

[0058] When executing the second heating mode, the first high-temperature heat medium flow channel 201 and the second high-temperature heat medium flow channel 20 are connected to form one flow channel, and the heat medium heated in both the first high-temperature heat exchanger 211 and the second high-temperature heat exchanger 212 is introduced into the first heat exchanger 81 and the second heat exchanger 82. The flow of the heat medium in the second heating mode is as follows Figure 4 shown.

[0059] exist Figure 4 In the figure, regarding the flow of heat medium, black solid lines represent pipes for circulation of high-temperature heat medium, single-dotted dashed lines represent pipes for circulation of low-temperature heat medium, and gray solid lines represent pipes for circulation of heat medium in a temperature range between high and low temperatures. The control unit 100 controls the first flow path switching unit V1 , the second flow path switching unit V2 , and the four-way valves 61 , 62 to circulate the heat medium in the heat medium circuit 10 as follows.

[0060] The control unit 100 connects the first high-temperature heat medium flow path 201 and the second high-temperature heat medium flow path 202 to form one flow path, and circulates the heat medium heated by passing through the first high-temperature heat exchanger 211 and the second high-temperature heat exchanger 212 . That is, the heat medium heated by passing through the first high-temperature heat exchanger 211 flows into the second heat exchanger 82 via the first flow path switching portion V1 .

[0061] The heat medium flowing into the second heat exchanger 82 exchanges heat with the air passing through the air flow passage 84, and then flows into the first heat exchanger 81 through the four-way valve 62 and the first flow passage switching unit V1, and exchanges heat with the air passing through the air flow passage 84. The heat medium flowing out of the first heat exchanger 81 flows into the second high-temperature heat exchanger 212 through the first flow passage switching unit V1 and the four-way valve 61 to be heated. The heat medium flowing out of the second high-temperature heat exchanger 212 repeatedly circulates through the four-way valve 62 and returns to the first high-temperature heat exchanger 211 through the first pump P1. Thus, the interior of the vehicle can be heated by the first heat exchanger 81 and the second heat exchanger 82.

[0062] In addition, during the circulation of the heat medium heated by the high-temperature heat exchanger 21, if the heat medium expands due to the increase in temperature and the amount of the heat medium becomes larger than the circuit capacity, the safety valve 57 becomes open, and the heat medium flows from the inlet 52 through the connection portion 28 into the container 50 and is stored.

[0063] The control unit 100 controls the first flow channel switching unit V1 and the second flow channel switching unit V2 so that the low-temperature heat medium flow channel 30 and the second flow channel 402 including the outdoor heat exchanger 45 in the temperature control target heat medium flow channel 40 become connected flow channels, and the heat medium cooled by passing through the low-temperature heat exchanger 31 circulates to the low-temperature heat medium flow channel 30 and the second flow channel 402.

[0064] That is, the heat medium cooled by passing through the low-temperature heat exchanger 31 flows into the outdoor heat exchanger 45 via the first flow switching part V1 and the second flow switching part V2, and after heat exchange with the external air, returns to the low-temperature heat exchanger 31 again via the second flow switching part V2 and the second pump P2.

[0065] By repeating the above cycle, the outdoor heat exchanger 45 can be used as a heat absorption source. In the flow path formed by connecting the low-temperature heat medium flow path 30 and the second flow path 402 of the temperature control target heat medium flow path 40, if the heat medium contracts due to a drop in temperature and the amount of the heat medium becomes smaller than the circuit capacity, the heat medium stored in the container 50 flows out from the outflow port 53 and flows into the low-temperature heat medium flow path 30 through the connection portion 38.

[0066] The control unit 100 controls the second flow path switching unit V2 and the four-way valve 61 so that the first flow path 401 and the third flow path 403 of the temperature control target heat medium flow path 40 become independent flow paths, and the heat medium circulates in the first flow path 401 and the third flow path 403 of the temperature control target heat medium flow path 40. That is, in the temperature control target heat medium flow path 40, the heat medium that sequentially passes through the PCU heat exchanger 44, the inverter heat exchanger 43, and the motor heat exchanger 42 and reaches a medium temperature by using the waste heat thereof is pumped to the battery heat exchanger 41 by the third pump P3 through the four-way valve 61 and the second flow path switching unit V2, thereby warming up the battery.

[0067] The heat medium whose temperature drops by warming up the battery in the battery heat exchanger 41 passes through the PCU heat exchanger 44, the inverter heat exchanger 43, and the motor heat exchanger 42 again to increase its temperature. By repeating such a cycle, the battery can be warmed up and the temperature of other onboard equipment can be adjusted. In addition, the ECH 46 provided downstream of the motor heat exchanger 42 can be operated to heat the heat medium as needed.

[0068] During the process of the heat medium circulating in the first flow channel 401 and the third flow channel 403 of the temperature control object heat medium flow channel 40, if the heat medium expands due to the increase in temperature and the amount of the heat medium becomes greater than the circuit capacity, the safety valve 58 becomes open, and the heat medium flows from the inlet 54 through the connection part 48 into the container 50 and is stored.

[0069] As described above, in the second heating mode, after the heat medium is preheated by the second high temperature heat exchanger 212 disposed on the downstream side of the circulation direction of the refrigerant, the heat medium is heated again by the first high temperature heat exchanger 211 disposed on the upstream side of the circulation direction of the refrigerant. At this time, in the refrigerant circuit R, since the first high temperature heat exchanger 211 is disposed on the upstream side of the circulation direction of the refrigerant than the second high temperature heat exchanger 212, as described above, the heat medium passing through the first high temperature heat exchanger 211 has a higher temperature than when passing through the second high temperature heat exchanger 212.

[0070] Moreover, the heat medium heated in two stages in the second high-temperature heat exchanger 212 and the first high-temperature heat exchanger 211 flows into the second heat exchanger 82 arranged on the downstream side of the air circulation direction of the air conditioning unit 80, and after exchanging heat with the air in the second heat exchanger 82, flows into the first heat exchanger 81 arranged on the upstream side of the air circulation direction, and exchanges heat with the air using the residual heat of the heat medium.

[0071] In this way, the air introduced into the air flow passage 84 is preheated in the first heat exchanger 81 before passing through the second heat exchanger 82, and is heated again in the second heat exchanger 82. That is, the residual heat of the heat medium after heat exchange with the air in the second heat exchanger 82 is used to heat the air in the first heat exchanger 81, so that efficient heat exchange can be performed between the heat medium and the air, and the heating efficiency of the air conditioning unit 80 can be improved. Furthermore, by using the first condenser 121 and the second condenser 122 in the refrigerant circuit R to perform heat exchange between the refrigerant and the heat medium in two stages, efficient heating operation can be achieved even with a refrigerant having a low critical temperature such as CO 2 .

[0072] (About cooling mode)

[0073] The cooling mode in this embodiment is an operation mode in which the cooled heat medium is also introduced into the battery heat exchanger 41 to cool the battery simultaneously with the cooling of the vehicle interior. In this cooling mode, in the outdoor heat exchanger 45, not only the heat of the refrigerant circuit R is dissipated, but also the heat medium that recovers the waste heat of various vehicle-mounted devices other than the battery heat exchanger 41, such as the motor heat exchanger 42, the inverter heat exchanger 43, and the PCU heat exchanger 44, is dissipated.

[0074] In the cooling mode, in the low-temperature heat medium flow path 30 , the refrigerant passing through the evaporator 14 exchanges heat with the heat medium passing through the low-temperature heat exchanger 31 , and the cooled heat medium is introduced into the first heat exchanger 81 and the second heat exchanger 82 of the air conditioning unit 80 .

[0075] The flow of the heat medium in the cooling mode of this embodiment is as follows Figure 5 As shown. Figure 5 In FIG. 1 , regarding the flow of the heat medium, the pipes through which the high-temperature heat medium circulates are indicated by black solid lines, and the pipes through which the low-temperature heat medium circulates are indicated by single-dot chain lines. The control unit 100 controls the first flow path switching unit V1 , the second flow path switching unit V2 , and the four-way valves 61 , 62 to circulate the heat medium in the heat medium circuit 10 as follows.

[0076] The control unit 100 controls the first flow channel switching unit V1, the second flow channel switching unit V2 and the four-way valve 62 so that the low-temperature heat medium flow channel 30 and the first flow channel 401 including the battery heat exchanger 41 in the temperature control target heat medium flow channel 40 become connected flow channels, and the heat medium cooled by passing through the low-temperature heat exchanger 31 circulates to the low-temperature heat medium flow channel 30 and the first flow channel 401.

[0077] That is, the heat medium cooled by passing through the low-temperature heat exchanger 31 flows to the second heat exchanger 82 via the first flow channel switching unit V1, and the heat medium flowing into the second heat exchanger 82 flows into the first heat exchanger 81 via the four-way valve 62 and the first flow channel switching unit V1, and exchanges heat with the air passing through the air flow channel 84.

[0078] The heat medium flowing out of the first heat exchanger 81 is repeatedly circulated through the first flow path switching unit V1 and the second flow path switching unit V2, is pumped to the battery heat exchanger 41 by the third pump P3, passes through the battery heat exchanger 41, and returns to the low-temperature heat exchanger 31 through the second pump P2 via the second flow path switching unit V2. Thus, the vehicle interior is cooled and the battery is cooled.

[0079] Furthermore, if the heat medium circulating in the low-temperature heat medium flow path 30 and the first flow path 401 contracts due to a drop in temperature and the amount of the heat medium becomes smaller than the circuit capacity, the heat medium stored in the container 50 flows out from the outflow port 53 and flows into the low-temperature heat medium flow path 30 via the connection portion 38 .

[0080] On the other hand, the control unit 100 controls the first flow channel switching unit V1, the second flow channel switching unit V2, and the four-way valves 61 and 62 so that the first high-temperature heat medium flow channel 201 and the second high-temperature heat medium flow channel 202 of the high-temperature heat medium flow channel 20 are connected to form one flow channel, and the first high-temperature heat medium flow channel 201 and the second high-temperature heat medium flow channel 202 are further connected to the second flow channel 402 and the third flow channel 403 in the temperature adjustment target heat medium flow channel 40. Thus, the heat medium heated by passing through the first high-temperature heat exchanger 211 and the second high-temperature heat exchanger 212 circulates to the first high-temperature heat medium flow channel 201, the second high-temperature heat medium flow channel 202, the second flow channel 402, and the third flow channel 403.

[0081] That is, the heat medium is heated by passing through the second high-temperature heat exchanger 212, and is pressure-sent to the first high-temperature heat exchanger 211 by the first pump P1 through the four-way valve 62, and is further heated in the first high-temperature heat exchanger 211. In this way, the heated heat medium flows into the outdoor heat exchanger 45 through the first flow path switching unit V1, the four-way valve 61, and the second flow path switching unit V2 in sequence, and again flows into the PCU heat exchanger 44, the inverter heat exchanger 43, the motor heat exchanger 42, and the ECH46 in sequence through the second flow path switching unit V2. Thereafter, a cycle of passing through the four-way valve 61 and returning to the second high-temperature heat exchanger 212 is repeated. Thus, the heat is dissipated by the first high-temperature heat exchanger 211, the second high-temperature heat exchanger 212, the PCU heat exchanger 44, the inverter heat exchanger 43, and the motor heat exchanger 42 by the outdoor heat exchanger 45.

[0082] At this time, when the heat medium circulating in the first high-temperature heat medium flow path 201, the second high-temperature heat medium flow path 202, the second flow path 402, and the third flow path 403 expands due to the temperature rise and the amount of the heat medium becomes greater than the circuit capacity, the heat medium flows into the container 50 and is stored. The heat medium flows into the container 50 in either a way that the safety valve 57 is opened and the heat medium flows into the container 50 from the inlet 52 through the connection part 28, or a way that the safety valve 58 is opened and the heat medium flows into the container 50 from the inlet 54 through the connection part 48.

[0083] As described above, in the cooling mode, the low-temperature heat medium can flow to both the first heat exchanger 81 and the second heat exchanger 82 of the air conditioning unit 80. In particular, the heat medium that has passed through the second heat exchanger 82 is made to flow to the first heat exchanger 81, so that the air before passing through the second heat exchanger 82 can be cooled in the first heat exchanger 81 in advance.

[0084] That is, the heat of the heat medium remaining after heat exchange with the air in the second heat exchanger 82 is used to cool the air in the first heat exchanger 81, thereby improving the air conditioning capacity of the air conditioning unit 80 and improving the thermal efficiency of the entire system.

[0085] Furthermore, by using the first condenser 121 and the second condenser 122 in the refrigerant circuit R to perform heat exchange between the refrigerant and the heat medium in two stages, efficient cooling operation can be achieved even with a refrigerant having a low critical temperature such as CO 2 .

[0086] In addition, as described above, in the control unit 100, the first flow path switching unit V1 is switched and controlled so that the heat medium flowing through the second heat exchanger 82 also flows to the first heat exchanger 81. That is, the first flow path switching unit V1 can be switched so that the heated or cooled heat medium flows to both the plurality of first heat exchangers 81 and the second heat exchangers 82 included in the air conditioning unit 80, thereby improving the air conditioning capacity when the heating mode is executed or the cooling mode is executed.

[0087] The embodiments of the present invention are described in detail with reference to the accompanying drawings, but the specific structure is not limited to these embodiments, and even if there are design changes that do not deviate from the scope of the present invention, they are also included in the present invention. In addition, as long as there are no special contradictions or problems in the purpose and structure of the above-mentioned embodiments, the technology of each other can be used for combination. Description of Reference Numerals

[0088] R: Refrigerant circuit, 1: Vehicle air conditioning device, 10: Heat medium circuit, 11: compressor, 12: condenser, 13: expansion valve, 14: evaporator, 15: storage, 20: High temperature heat medium flow channel, 21: High temperature heat exchanger, 30: low temperature heat medium flow channel, 31: low temperature heat exchanger, 40: Temperature control target heat medium flow channel, 41: Battery heat exchanger, 42: Motor heat exchanger, 43: Inverter heat exchanger, 44: PCU heat exchanger, 45: Outdoor heat exchanger, 46: ECH, 50: container, 52: inlet, 53: outlet, 54: inlet, 57: safety valve, 58: safety valve, 28, 38, 48: connection part, 61, 62: four-way valve, 80: air conditioning unit, 81: first heat exchanger, 82: second heat exchanger, 83: suction port, 84: air flow channel, 100: control unit, 200: vehicle controller, 300: air conditioning operation unit, V1: first flow channel switching portion, V2: second flow channel switching portion.

Claims

1. A vehicle air conditioning device, characterized in that: have: Refrigerant circuit; a heat medium circuit for circulating a heat medium heated or cooled by the refrigerant circuit; and The air conditioning unit has a plurality of heat exchangers disposed in an air flow passage through which the heat medium circulating in the heat medium circuit flows, and controls the temperature of the air passing through the air flow passage and supplies the air to the vehicle interior. The refrigerant circuit includes a first refrigerant-heat medium heat exchanger and a second refrigerant-heat medium heat exchanger which are sequentially arranged along the circulation direction of the refrigerant and dissipate heat of the refrigerant to the heat medium circulating in the heat medium circuit. The heat medium circuit includes a flow path switching unit that switches a flow path in which the heat medium that has passed through either the first refrigerant-heat medium heat exchanger or the second refrigerant-heat medium heat exchanger flows into at least one of the plurality of heat exchangers, and switches a flow path in which the heat medium that has passed through both the first refrigerant-heat medium heat exchanger and the second refrigerant-heat medium heat exchanger flows into the plurality of heat exchangers.

2. The vehicle air conditioning device according to claim 1, characterized in that: The flow path switching unit switches so that the heat medium having passed through the second refrigerant-heat medium heat exchanger flows into the heat exchanger disposed on the upstream side of the air flow path or flows into the first refrigerant-heat medium heat exchanger.

3. The vehicle air conditioning device according to claim 1, characterized in that: The flow path switching unit allows the heat medium that has passed through the first refrigerant-heat medium heat exchanger to flow into the heat exchanger disposed on the downstream side of the air flow path, and allows the heat medium that has passed through the second refrigerant-heat medium heat exchanger to flow into the heat exchanger disposed on the upstream side of the air flow path.

4. The vehicle air conditioning device according to claim 1, characterized in that: The flow path switching unit allows the heat medium that has passed through the second refrigerant-heat medium heat exchanger to flow into the first refrigerant-heat medium heat exchanger, and then into the plurality of heat exchangers of the air conditioning unit.

5. The vehicle air conditioning device according to claim 1, characterized in that: The flow path switching unit allows the heat medium that has sequentially passed through the second refrigerant-heat medium heat exchanger and the first refrigerant-heat medium heat exchanger to flow into the heat exchanger disposed on the upstream side of the air flow path after passing through the heat exchanger disposed on the downstream side of the air flow path.

Images